In recent years, in accordance with reduction in size, reduction in thickness, and high performance of mobile terminal equipment represented by a mobile phone, the further reduction in thickness and the further reduction in size of a chip component of an electronic component have been required. However, with mere reduction in size and mere reduction in thickness of the chip component, it is expected that there will be great difficulty in performing a manufacturing step such as mounting of the chip components on a circuit substrate or the like.
On the contrary, in Unexamined Japanese Patent Publication No. 9-171959, an electronic component having an organic film of a predetermined size and a plurality of functional components mounted on this film in a predetermined order and a method for manufacturing thereof are disclosed. This method for manufacturing the electronic component is characterized by having a first feeding step for feeding a tape with a predetermined width, a second feeding step for feeding a plurality of tapes on which the functional components are mounted, and a mounting step for mounting a plurality of functional components on a tape to be supplied in the first feeding step in a predetermined order.
In this composite electronic component, a resistor, a capacitor, and an inductor or the like are mounted in plural on one piece of a unit substrate. Accordingly, as compared to a method for individually mounting an electronic component manufactured individually, for example, a chip component or the like on a circuit substrate, this composite electronic component can be made with high density. However, this composite electronic component is composed in such a manner that the electronic components formed by a thin film are aligned on a flat surface and in such an arrangement configuration on a flat surface, there is a limitation in an integration degree of the electronic component.
On the contrary, in Unexamined Japanese Patent Publication No. 2005-45112, for example, it is disclosed that the electronic components are laminated and formed on a base material to be made into a three-dimensional configuration. This component-incorporated flexible circuit substrate has a base material made of a flexible heat-resistant resin film; and at least one piece of a thin film passive component configured by sandwiching a functional thin film formed by using any material of a dielectric body, a resistor, and a conductor by a first electrode circuit wiring and a second electrode circuit wiring, which are formed by a conductor thin film. Then, the component-incorporated flexible circuit substrate is configured in such a manner that the film thickness of any of the first electrode circuit wiring, the second electrode circuit wiring, and the functional thin film is thinner than that of the base material and a plurality of layers of the thin film passive components is laminated on the base material to form a passive component lamination.
This component-incorporated flexible circuit substrate uses a technique to directly form a functional thin film such as a capacitor and a resistor of a thickness not more than 1 μm on a thin organic film base material, and as compared to a conventional chip component, it is possible to make the thickness into about 1/100. Further, if a base material that is thin and flexible is used, it is also possible to arrange a device in limited space. In addition, by laminating the sheets having a device function with each other and connecting them, a wiring length between the devices can be made very short, so that transmission loss of a high frequency signal can be reduced. Further, since a plurality of passive components can be laminated, it is possible to largely improve the freedom of design of a circuit.
In the Unexamined Japanese Patent Publication No. 9-171959, since each electronic component is formed by a thin film forming method or a printing method, as compared to a conventional chip component, each electronic component can be made largely thin. In addition, by examining individual electronic components in advance or trimming them, properties of the individual electronic components can be adjusted, so that only a good-quality product is mounted on a master tape to be made into a composite electronic component. However, according to this example, an electronic component of a flat surface configuration to align and mount respective electronic components on a flat surface is only obtained.
On the other hand, in Unexamined Japanese Patent Publication No. 2005-45112, since the electronic components are laminated three-dimensionally by using the thin film forming method, reduction in size and reduction in thickness of the electronic component can be made. Although, according to this example, for example, an example that a capacitor, capacitors with each other, or a capacitor and an inductor are laminated is indicated, in order to laminate them by using the thin film forming method, a film formation step and a pattern processing step should be repeated many times, so that the step is made very complex. In addition, the case that the previously manufactured thin film electronic component becomes defective due to the influence of a manufacturing step of the thin film electronic component to be laminated on this is easily generated. For example, in the case of forming a resistor on the capacitor that has been manufactured previously, short-circuiting of a capacitor and deterioration of a property are easily generated by heating when forming the resistor and etching to make a predetermined pattern or the like. As a result, a yield rate as a laminated finished component-incorporated flexible circuit substrate is made low, so that there is a problem that the cost becomes high.